Answer:
3/9
Step-by-step explanation:
15/45
divide both sides by a factor of each number; I'll be using 5.
3/9
It didn't have to be 5, I could have used 3, but in that case It wouldn't have been it's simplest form and I would have to divide again by another factor.
Answer:
Y=-2/3x+6
Step-by-step explanation:
Y=-2/3x+b
2=-2/3•6+b
2=-4+b
6=b
1/6 x 2 = 2/12
3/4 x 3 = 9/12
2/12 + 9/12 = 11/12
Altogether, Keisha bought 11/12 of a tank of gas.
Answer:
a) The half life of the substance is 22.76 years.
b) 5.34 years for the sample to decay to 85% of its original amount
Step-by-step explanation:
The amount of the radioactive substance after t years is modeled by the following equation:

In which P(0) is the initial amount and r is the decay rate.
A sample of a radioactive substance decayed to 97% of its original amount after a year.
This means that:

Then



So

(a) What is the half-life of the substance?
This is t for which P(t) = 0.5P(0). So







The half life of the substance is 22.76 years.
(b) How long would it take the sample to decay to 85% of its original amount?
This is t for which P(t) = 0.85P(0). So







5.34 years for the sample to decay to 85% of its original amount